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. 2017 Jun 1;123(11):2070-2079.
doi: 10.1002/cncr.30615. Epub 2017 Mar 6.

Dietary isoflavone intake and all-cause mortality in breast cancer survivors: The Breast Cancer Family Registry

Fang Fang Zhang  1 , Danielle E Haslam  1 , Mary Beth Terry  2 , Julia A Knight  3   4 , Irene L Andrulis  3   4 , Mary B Daly  5 , Saundra S Buys  6 , Esther M John  7   8
Affiliations

Dietary isoflavone intake and all-cause mortality in breast cancer survivors: The Breast Cancer Family Registry

Fang Fang Zhang et al. Cancer. .

Abstract

Background: Soy foods possess both antiestrogenic and estrogen-like properties. It remains controversial whether women diagnosed with breast cancer should be advised to eat more or less soy foods, especially for those who receive hormone therapies as part of cancer treatment.

Methods: The association of dietary intake of isoflavone, the major phytoestrogen in soy, with all-cause mortality was examined in 6235 women with breast cancer enrolled in the Breast Cancer Family Registry. Dietary intake was assessed using a Food Frequency Questionnaire developed for the Hawaii-Los Angeles Multiethnic Cohort among 5178 women who reported prediagnosis diet and 1664 women who reported postdiagnosis diet. Cox proportional-hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: During a median follow-up of 113 months (approximately 9.4 years), 1224 deaths were documented. A 21% decrease was observed in all-cause mortality for women who had the highest versus lowest quartile of dietary isoflavone intake (≥1.5 vs < 0.3 mg daily: HR, 0.79; 95% confidence interval CI, 0.64-0.97; Ptrend = .01). Lower mortality associated with higher intake was limited to women who had tumors that were negative for hormone receptors (HR, 0.49; 95% CI, 0.29-0.83; Ptrend = .005) and those who did not receive hormone therapy for their breast cancer (HR, 0.68; 95% CI, 0.51-0.91; Ptrend = .02). Interactions, however, did not reach statistical significance.

Conclusions: In this large, ethnically diverse cohort of women with breast cancer living in North America, a higher dietary intake of isoflavone was associated with reduced all-cause mortality. Cancer 2017;123:2070-2079. © 2017 American Cancer Society.

Keywords: breast cancer; breast cancer survivors; isoflavone; mortality; soy; survival.

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Conflict of interest statement

Conflict of Interests Statement: The authors have no conflicts of interests to disclose.

Figures

Figure 1
Figure 1. Types of Isoflavone Intake and All-Cause Mortality in Women With Breast Cancer: The Breast Cancer Family Registry
The three bars with different gray colors correspond to the harzard ratios (HRs) compring the highest quartile (Q4), the third quartile (Q3) and the second quartile (Q2) to the lowest quartile (Q1) for different types of isoflavone intake. The three lines correspond to the 95% confidence intervals (CIs).
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References

    1. Setchell KD, Cassidy A. Dietary isoflavones: biological effects and relevance to human health. J Nutr. 1999 Mar;129(3):758S–767S. - PubMed
    1. Messina M, McCaskill-Stevens W, Lampe JW. Addressing the soy and breast cancer relationship: review, commentary, and workshop proceedings. Journal of the National Cancer Institute. 2006 Sep 20;98(18):1275–1284. - PubMed
    1. Velentzis LS, Woodside JV, Cantwell MM, Leathem AJ, Keshtgar MR. Do phytoestrogens reduce the risk of breast cancer and breast cancer recurrence? What clinicians need to know. European journal of cancer (Oxford, England : 1990) 2008 Sep;44(13):1799–1806. - PubMed
    1. Research WCRFAIfC. Diet, nutrition, physical activity, and breast cancer survivors. 2014 http://www.wcrf.org/sites/default/files/Breast-Cancer-Survivors-2014-Rep....
    1. Chi F, Wu R, Zeng YC, Xing R, Liu Y, Xu ZG. Post-diagnosis soy food intake and breast cancer survival: a meta-analysis of cohort studies. Asian Pacific journal of cancer prevention : APJCP. 2013;14(4):2407–2412. - PubMed

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